Asset tracking is important for many industries. For example, a hospital may endeavor to track its equipment or a grocery store may want to track the movement of shopping carts for analytics purposes. As another example, a factory or construction site may want to track the whereabouts of workers to ensure their safety. In some situations, tracking assets in the visible domain is difficult due to low light conditions, excessive ambient light, obstructions, and the like.
Printed codes (e.g., QR codes and bar codes) may be used to track assets in the visible domain. However, printed codes are difficult to detect and read at a distance even under optimal lighting. Furthermore, a great amount of computational power may be needed to read such a code (e.g., 8 million pixels in a 4K image) without accounting for errors.
Radio frequency identification (RFID) tags may also be used to track assets in some situations. However, RFID tags cannot be read with geographic accuracy (e.g., approximately 1 to 3 meters of error). Furthermore, passive RFID tags do not convey info outside of their unique identification or serial number. On the other hand, active RFID tags are able to convey additional information, but active RFID tags are expensive and have limited power.
In accordance with common practice the various features illustrated in the drawings may not be drawn to scale. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may not depict all of the components of a given system, method or device. Finally, like reference numerals may be used to denote like features throughout the specification and figures.